TO STUDY EFFECT OF SALT SOLUTION ON PERMEABILITY OF SOILS

Abstract

Since soils consists of discrete particles, the void spaces between the particles are interconnected and may be viewed as a highly complex and intricate network of irregular tubes. The flow through soils is based on conventional experiment performed by Darcy who acquainted experimentally determined constant called coefficient of permeability. This constant is obviously reflective of the permeability of a certain medium to a certain fluid, and it depends on the properties of both the porous medium and pervade
fluid. For the penetrable medium it is the size of the channels in the void network that is of key importance, and this depends on the representative grain size diameter, the gradation factor delineating the shape of grain size distribution curve, the shape factor of the grains and the porosity of the medium. Among the fluid properties viscosity and density of fluids are of key importance. In the present study, permeability measurements were taken using sands of different sizes as the pervade mediums. The pervade fluids that
were employed were pure water (tap water) and salt (NaCl) solutions of different concentrations (5g/l to 71g/l). Six different sands S1 to S6 were used which were classified on the basis of their increasing representative sizes 0.12mm,0.15mm,0.18mm,0.20mm,0.22mm and 0.25mm respectively. To rule out the effects due to temperature differences and fluid flow duration through sands, the permeability results were standardized at 20°C and the discharge readings were taken after two hours of the establishment of steady
conditions respectively. It was observed that the permeability increased with increase in the concentration of salt solution. Also effect on the density, viscosity and dielectric constant were also analyzed